$(function () {
  var $main = $(".main");
  var $list = $(".talk_list");
  var $drager = $(".drager");
  var $mainh = $main.outerHeight(false);
  var $listh = $list.outerHeight(false);

  var $rate = $mainh / $listh;
  var $dragh = $mainh * $rate;
  var $top = 0;
  $drager.css({ height: $dragh });

  $drager.draggable({
    containment: "parent",
    drag: function (ev, ui) {
      $top = ui.position.top;
      $list.css({ top: -$top / $rate });
    },
  });

  $(window).resize(function () {
    resetui();
  });

  //var timer = null;
  var flag = false;

  $main.mousewheel(function (ev, delta) {
    //console.log(delta);
    //clearTimeout(timer);
    //timer = setTimeout(function(){
    // 向上滚动正值，向下滚动负值
    if (flag) {
      return;
    }

    flag = true;

    setTimeout(function () {
      flag = false;
    }, 300);

    if ($listh <= $mainh) {
      return;
    } else {
      if (delta > 0) {
        $top = $top - 60;
        if ($top < 0) {
          $top = 0;
        }
        $drager.animate({ top: $top }, 200);
        $list.animate({ top: -$top / $rate }, 200);
      } else {
        $top = $top + 60;
        if ($top > $mainh - $dragh) {
          $top = parseInt($mainh - $dragh);
        }
        $drager.animate({ top: $top }, 200);
        $list.animate({ top: -parseInt($top / $rate) }, 200);
      }
    }

    //},300);
  });
  if ($listh <= $mainh) {
    $(".drag_bar").hide();
    $(".drager").hide();
  }

  function resetui() {
    $mainh = $main.outerHeight(false);
    $listh = $list.outerHeight(false);
    $rate = $mainh / $listh;
    $dragh = $mainh * $rate;
    $drager.css({ height: $dragh });

    if ($listh <= $mainh) {
      $(".drag_bar").hide();
      $drager.hide();
      $list.css({ top: 0 });
    } else {
      $(".drag_bar").show();
      $drager.show();
      $drager.css({ top: $mainh - $dragh });
      $list.css({ top: -($listh - $mainh) });
    }
  }

  window.resetui = resetui;
});
